Magnetic and Mössbauer study of Mg_0.9Mn_0.1Cr _x Fe_2−x O₄ ferrites

Abstract

The ferrites Mg_0.9Mn_0.1Cr _x Fe_2−x O₄ ($0 \leqslant {\text{x}} \leqslant 0.9$) were prepared using the conventional double sintering method. The XRD showed that the samples maintain a single spinel cubic phase. The Mössbauer measurements were carried out at room and liquid nitrogen temperatures. From the area ratios of the A and B sites, it was found that the Fe cation population of the A and B sites decreases in proportion to Cr concentration. The contact hyperfine fields at the A and B sites were found to decrease with increasing Cr contents. This was found to be in approximate agreement with the results of magnetization measurement. The distributions of Mg and Mn cations versus Cr concentration were also determined using the Mössbauer and magnetization results. The Curie temperatures were determined and found to agree with the reported values. As the Cr contents increases the relative magnetization, was found to increase at low temperatures and decreases at higher temperatures.